Zugvogel vs. Wandervogel
The German words Zugvogel and Wandervogel are both related to the concept of migrating or wandering, but they are used in very different contexts. While Zugvogel is the standard biological term for an actual migratory bird, Wandervogel is used almost exclusively as a metaphor to describe a person who loves hiking, traveling, or roaming the world freely.
Zugvogel
B2The word Zugvogel translates directly to migratory bird and is used in biology and everyday language strictly to describe real birds that fly to warmer climates in the winter and return in the spring.
Der Kranich ist ein bekannter Zugvogel in unseren Breitengraden.
(The crane is a well-known migratory bird in our latitudes.)
Im Herbst sammeln sich die Zugvögel über den Feldern, um gemeinsam in den Süden zu fliegen.
(In autumn, the migratory birds gather over the fields to fly south together.)
Der fortschreitende Klimawandel beeinflusst das Flugverhalten und die Routen vieler Zugvögel.
(Progressing climate change is affecting the flight behavior and routes of many migratory birds.)
Biologen befestigten kleine Funksender an dem Zugvogel, um seine lange Reise genau zu verfolgen.
(Biologists attached small radio transmitters to the migratory bird to track its long journey accurately.)
Schwalben und Störche sind die wohl typischsten Zugvögel in der europäischen Natur.
(Swallows and storks are arguably the most typical migratory birds in European nature.)
Wandervogel
C1Although Wandervogel literally translates to wandering bird, it is used metaphorically to describe a human who has a strong passion for hiking, traveling, and exploring nature. It is also the historical name of a famous German youth movement from the early twentieth century that promoted hiking and a back-to-nature lifestyle.
Mein Onkel war schon immer ein echter Wandervogel und hat im Laufe seines Lebens die ganze Welt bereist.
(My uncle has always been a true globetrotter and has traveled the whole world over the course of his life.)
Sie ist ein absolut rastloser Wandervogel und bleibt niemals lange an ein und demselben Ort.
(She is an absolutely restless wanderer and never stays in one and the same place for long.)
Jedes Wochenende packt der Wandervogel seinen Rucksack für ein neues Abenteuer in den Bergen.
(Every weekend, the avid hiker packs his backpack for a new adventure in the mountains.)
Als Teenager schloss er sich voller Begeisterung den Idealen der historischen Wandervögel an.
(As a teenager, he enthusiastically joined the ideals of the historical Wandervogel movement.)
Trotz seines fordernden Büroberufs blieb er in seinem Herzen immer ein freier Wandervogel.
(Despite his demanding office job, he always remained a free roaming spirit in his heart.)
Summary
In short, if you are talking about actual birds flying south for the winter, you must use Zugvogel. However, if you want to describe a person who passionately loves to travel, hike, or wander from place to place, Wandervogel is the structurally correct and culturally poetic term.